In-mold process uses light for decorating parts.

Injection molded automotive parts that emit light when voltage is applied are innovative applications of in-mold decorating. Developed by automotive custom molder Key Plastics LLC in Farmington Hills, Mich., electroluminescence (EL) can light a wide area or an entire plastic part instead of just a point or line. It also eliminates the need for light fixtures, light pipes, or switching mechanisms. Power consumption is low.

The process uses a special five-layer sheet that has a phosphorus layer at the core, plus two dielectric layers for capacitance and two skin layers that contain a conductive silver/graphite material. A clear coat protects the sheet, which can accept screen-printing and graphics. The thin sheet is preformed into a shape by thermoforming, pressure forming, or cold forming. Then it is placed in the injection mold and back or front molded

Key Plastics buys the El, sheet from an unnamed source and insert molds it with polyester or polycarbonate. Current uses include instrument-cluster backlighting, gearshift consoles, door window and lock buttons, and semi-transparent rear roof liners. Key Plastics is also exploring applications in car door handles, door kick panels, air-duct bezels, and hood-release latches.